1. Field
The present invention relates to a technology for estimating an expression of a person in an image.
2. Related Art
Nowadays, with the progress of an image analysis technology, a face portion of a person can be specified from an image, or an expression of the face can be estimated. For example, in Japanese Unexamined Patent Publication No. 2010-066844, the face is detected from a moving image content to recognize the expression of the face, and a feeling of the person is determined from existence or non-existence or size of the motion of the person in which the face is detected and existence or non-existence or volume of a sound made by the person. In Japanese Unexamined Patent Publication No. 2005-237561, an expression and a body motion of the person image included in image information are detected, and mind and body conditions of a user are detected based on the expression and the body motion as well as sound information and biological information which are acquired by sensors.
Sometimes false estimation, in which the expression different from the feeling of the person in the image is estimated, is generated in the expression estimation based on the image. For example, because the expression of hate and the expression of anger are similar to each other, sometimes the expression is estimated to be anger in the case that the person in the image feels the hate, or the expression is estimated to be hate in the case that the person feels the anger. Therefore, there is a demand to enhance accuracy of the expression estimation such that the generation of the false estimation is minimized.
However, in the conventional technology as described above, unfortunately the accuracy of expression estimation of the person in the image cannot be enhanced. This is because, in the technology of Japanese Unexamined Patent Publication No. 2010-066844, the face expression is used as one of factors determining the feeling of the person, but the technology is not aimed at the estimation of the expression. Similarly, in the technology of Japanese Unexamined Patent Publication No. 2005-237561, the expression is used as one of factors detecting the mind and body conditions of the user, but the technology is not aimed at the estimation of the expression. Therefore, the accuracy of the expression estimation cannot be enhanced.